Electrical circuit breaker of the gas blast type with arrangement for inspection of blast valve

ABSTRACT

An electrical circuit breaker of the gas blast type includes a hollow columnar insulator atop which are supported circuit breaker components such as a high-pressure housing within which gas such as SF6 is stored in readiness for delivery to a switch contact chamber via a low-pressure housing under the control of a blast valve which is accessible for inspection through the lowpressure housing. A two-position blocking-off member is provided to control communication between the low-pressure housing and the columnar insulator on the one hand, and between the low-pressure housing and the high-pressure housing on the other hand. In a first position of the blocking-off member corresponding to the operating state of the circuit breaker, communication is established between the low-pressure housing and the columnar insulator; in the second position, both the columnar insulator and high-pressure housing are blocked off from the low-pressure housing thereby enabling the latter to be opened for inspection of the blast valve.

United States Patent Primary Examiner-Robert S. Macon Attorney-Pierce, Scheffler & Parker ABSTRACT: An electrical circuit breaker of the gas blast type includes a hollow columnar insulator atop which are supported circuit breaker components such as a high-pressure housing within which gas such as SF, is stored in readiness for delivery to a switch contact chamber via a low-pressure housing under the control of a blast valve which is accessible for inspection through the low-pressure housing. A two-position blocking-off member is provided to control communication between the low-pressure housing and the columnar insulator on the one hand, and between the low-pressure housing and the high-pressure housing on the other hand. in a first position of the blocking-off member corresponding to the operating state of the circuit breaker, communication is established between the low-pressure housing and the columnar insulator; in the second position, both the columnar insulator and highpressure housing are blocked off from the low-pressure housing thereby enabling the latter to be opened for inspection of the blast valve.

[7 21 Inventor Dieter Floessel Fislisbach, Switzerland [21] Appl. No. 55,526 [22] Filed July 16, 1970 [45] Patented Dec. 28, 1971 [73] Assignee Aktiengesellschalt Brown, Boveri & Cie

Baden, Switzerland [32] Priority July 23, 1969 [33] Switzerland [3 1 1 1246/69 [54] ELECTRICAL CIRCUIT BREAKER OF THE GAS BLAST TYPE WITI-I ARRANGEMENT FOR INSPECTION OF BLAST VALVE 5 Claims, 1 Drawing Fig.

[52] US. Cl 200/148 R [51] Int. Cl H01h 33/80 [50] Field of Search 200/148, 148 13,148 D, 148 E v [56] References Cited UNITED STATES PATENTS 3,221,129 11/1965 Young ZOO/148B 3,311,727 3/1967 Picard 200/148 swam m Dieier FloesseL Gum;

PATENTED UEE28 197p PwSUHI QLX Pm ELECTRICAL CIRCUIT BREAKER OF THE GAS BLAST TYPE WITH ARRANGEMENT FOR INSPECTION OF BLAST VALVE The present invention relates to an improved construction for a heavy duty electrical circuit breaker or switch of the gasblast type in which separation of the contacts and extinction of the arc drawn between the contacts is facilitated by a blast of pressurized gas, the gas being particularly SF,,, and which is stored in a high-pressure chamber located adjacent the switch contact chamber atop a hollow columnar insulator in readiness for use in contact separation and arm extinction when admitted to the contact chamber through a blast valve, the thereafter flowing into a low-pressure chamber from which it is ultimately returned to the high-pressure chamber after purification and repressurization.

A columnar-type gas blast switch filled with gaseous SF, and of the closed gas circuit type is known which is subdivided into several closed chambers such as the switch contact chamber, transmission head, and hollow columnar insulator through which the actuating rod for the blast valve extends, the various chambers being placed in communication with one another only through valves which close at a certain pressure differential between two chambers of the switch and which are constructed in the form of plate relief valves acting, if necessary, in both directions. Such a switch construction is disclosed in German Pat. DAS 1,102,858. It has also been suggested to arrange the blast valve of the switch between the high-pressure chamber and the low-pressure chamber at the upper end of the columnar insulator so that it is accessible from the outside for purposes of inspection, and to arrange ahead of it a socalled blocking-off member which serves to seal off the high and low-pressure chambers from the exterior during the inspection thereby preventing any moisture, which is harmful to the SF from entering the chambers.

The principal object of this invention is to provide an improved structural arrangement for the blocking off member which functions to effect the necessary sealing-off of the highand low-pressure chambers for inspection of the blast valve but which does not require that any pressure differential be first established.

One suitable embodiment of the invention will now be described and is illustrated in the accompanying drawing which shows the upper portion of a columnar-type gas blast switch in central vertical section, the section being divided along a centerline into essentially two views, the view to the left of the centerline showing the components in the operating state of the switch, and the other view to the right of the centerline showing the components in the nonoperating state, i.e., when it is desired to make an inspection of the blast valve.

With reference now to the drawing, the upper portion of a columnar-type hollow insulator structure is indicated at 1. Supported atop the hollow insulator column 1 is a metallic housing structure 2 which carries the full voltage of the switch contacts. Connected to at least one side of the housing 2 at the place indicated by. numeral 4 is a switch chamber containing the switch contacts which are actuated by the pressurized gas. The switch contact chamber has riot been illustrated since it is conventional and is not believed to be essential to an understanding of the present invention.

Located atop and contiguous to the housing 2 is another housing 7 providing a chamber therein for storage of the SF at high pressure ready for admission to the switch contact chamber when the blast valve 9 is actuated. The blast valve is mounted at the upper end of an insulated actuating rod 10 which extends upwardly through the center of insulator column 1 and housing 2.

The so-called blocking-off member in accordance with the invention for sealing off the high-pressure chamber from the low-pressure chamber and the two chambers from the atmosphere is indicated generally at 6. As can be seen from the drawing, the blocking-off member 6 is seen to be tubular and is located in a vertical attitude concentrically with the axis of the columnar insulator 1, housing 2 and high-pressure housing 7. lt surrounds the blast valve actuator rod 10 and is guided vertically in a sleeve portion 2a of the housing 2. It is also provided with a series of apertures 6a in the wall thereof which communicate with corresponding ports 2b in the wall of sleeve portion 2a so as to place the interior of the housing 2 in communication with the interior of insulator column 1, in the operating state of the switch, i.e., in the position indicated to the left of the vertical centerline of the drawing. The blockingoff member 6 is also provided with an internal transverse wall 6d containing a central opening to permit pass-through of the blast valve actuating rod 10. The opening in the wall 64' is sized to substantially the diameter of rod 10 so that the wall 6d will function as a piston in a manner to be later explained.

The upper portion 6c of the blocking-off member is seen to be of larger diameter than the lower part and is connected to the latter by means of an upwardly sloping spider 62. This upper portion 60 is guided for vertical movement in a centrally located sleeve part 7b of the high-pressure housing 7, and is provided with a series of apertures 6b in the wall thereof which communicate with corresponding ports 7a in sleeve 7b so as to place the interior of the high-pressure housing 7 in communication with the interior of the upper portion 6c of the blocking-off member, at a location above the blast valve 9, in the operating state of the switch.

It will also be seen from the drawing that the interior wall of the upper portion 60 of the blocking-off member serves as a cylindrical guide for the blast valve 9. The upper end of the portion 60 terminates in an end wall 6f located above the blast valve 9 and apertures 6b. Since, in the position of the blocking-off member 6 shown to the left of the centerline, the interior of the upper portion 6c communicates with the highpressure chamber 5 within housing 7, a force is always exerted on the latter acting in theupward direction. To counteract this force, and maintain the blocking-off member in the position shown to the left of the centerline, it will be seen that a cylindrical member in the form of a sleeve 11 is slidably guided in the sleeve part 7b of housing 7, and that the lower end of this sleeve bears upon the end wall (if. The upper end of sleeve 11 terminates in a head part 11a of larger diameter, and the peripheral portion thereof is provided with a series of circumferentially spaced apertures 11b through which pass a correspondingly located series of circumferentially spaced, vertically extending threaded stay bolts 12 which are fixed at their lower ends to a ring 13 which is secured, as by welding, to the upper end wall of housing 7. Screw-down nuts 14 on the bolts 12 above the head part 11a serve to hold the latter and hence the sleeve 11 in the down position, i.e., to the left of the centerline.

If it is now desired to make an inspection of the blast valve or other parts of the switch assembly involving access to the interior 3 of the housing part 2, it is essential that the interior 3 be isolated both from the high-pressure chamber 5 and from the interior of the hollow insulator column 1. To effect this isolation, the nuts 14 are backed off from the head permitting the latter to rise under the high gas pressure existing within the blocking member beneath the end wall 6f, from the position shown at the left side of the center line to that depicted at the right side of the centerline. When this latter position is reached, it will be seen that the apertures 6b are no longer in registration with the ports 7a and hence the highpressure chamber 5 is blocked off from any possible communication with the interior 3 of housing 2 regardless of the position of the blast valve 9. Similarly, the interior 3 of housing 2 is blocked off from any possible communication with the interior of the hollow insulator 1 since the apertures 6a are no longer in registration with the ports 2b.

[f the pressure of the gas within housing 2 is now released such as by opening the housing to provide access, the upper position of the blocking member 6 is maintained since the pressure of the gas locked within the hollow insulator l presses upward on the transverse partition 6d functioning as a piston.

Upon completion of the inspection, the blocking member 6 is returned to its original lower position by turning down the nuts 14 on the studs 12.

For refilling the chamber of the high-pressure housing 7 with pressurized SF gas, a refill line 8 extends downwardly from the bottom of housing 7 along the exterior of housing 2 and then enters the interior of the hollow insulator through suitable channels provided in the bottom wall of housing 2. The line 8 is electrically insulated, at least to the extent of the section which extends downward through insulator column ll.

lclaim:

1. In an electrical circuit breaker structure of the gas blast type, the combination comprising a hollow columnar insulator, a low-pressure housing supported atop said columnar insulator and which leads to a chamber containing the circuit breaker contacts, a high-pressure housing storing a pressurized gas such as SP for contact separation and are extinction and which is located adjacent said low-pressure housing, a blast valve-controlling communication between said highpressure housing and said low-pressure housing, and a blocking-off member controlling communication between said high-pressure housing and said low-pressure housing and also controlling communication between the interior of said columnar insulator and said low-pressure housing, said blocking-off member being movable from a first position corresponding to the operating state of said circuit breaker and wherein said columnar insulator communicates with said lowpressure housing to a second position corresponding to the inspection state of said circuit breaker and wherein both said columnar insulator and said high-pressure housing are blocked off from said low-pressure housing.

2. An electrical circuit breaker structure as defined in claim 1 wherein said blocking-off member includes a lower tubular part slidably arranged in a first guide sleeve located withinsaid low-pressure housing and which communicates with said columnar insulator, said lower tubular part of said blockingoff member being provided with apertures which when said blocking-off member occupies a lower position corresponding to the operating state of the circuit breaker are in registration with ports in said first guide sleeve to establish communication between said low-pressure housing and the interior of said columnar insulator, said blocking-ofi' member further including an upper tubular part slidably arranged in a second guide sleeve established by an inner cylindrical wall of said highpressure housing, said upper tubular part of said blocking-off member being provided with apertures which when said blocking-off member occupies its lower position are in registration with ports in said second guide sleeve to establish communication between said high-pressure housing and said lowpressure housing when said blast valve is actuated to effect a disconnection of the circuit breaker contacts, said blockingoff member being movable to an upper position corresponding to an inspection state of the circuit breaker to shift the apertures in the lower and upper tubular parts thereof out of registration with their respectively associated ports in said first and second guide sleeves thereby to block off communication between said low-pressure housing and said columnar insulator and high-pressure housing respectively.

3. An electrical circuit breaker structure as defined in claim 2 wherein said blast valve is mounted for sliding movement as a piston in the upper tubular part of said blocking-off member which is closed off at guide sleeve whereby the pressurized gas from said high-pressure housing is admitted to the interior of and applies an upward force against said blocking-off member tending to shift said blocking-off member to its upper position, and means for applying a releasable counter force to hold said blocking-off member in its lower position.

4. An electrical circuit breaker structure as defined in claim 3 wherein said means for applying a releasable counter force holding said blocking-off member in its lower position is constituted by a sleeve member located above and which bears upon the upper tubular part of said blocking-off member, said sleeve member being uided for sliding movement in said second guide sleeve, sai sleeve member terminating in a head including a plurality of circumferentially spaced apertures through which pass upstanding threaded stay b'olts provided with nuts which bear upon the head.

5. An electrical circuit breaker structure as defined in claim 3 wherein said blast valve is actuated by a rod extending upward through said columnar insulator and said tubular blocking-off member, the interior of said blocking-off member being provided with a transverse wall through which said blast valve actuator passes with a snug fit thereby enabling said transverse wall to function as a piston subjected to the gas pressure within said columnar insulator for applying an upward force to said blocking-off member.

Yam-2N9; v 3.6%1521 Dated December- 28'. 1971 Y Ihyex". to: (s) DIE'I'ER FLOESSEL is cdrtificd char. error appears in. the shove -identified patent:

hereby corrected as shown below:

3nd aha; said Letcers'Pa'cent am Claim. 3 'l'l'ne between the words "at"- 4 and .uiiief insert the following: Q

112s upper end, said bias; v alve normally 5 u py1 g a 'po si t idn below the]. ports in f" -s'a1d sond Kismp) was -ROBER'T-4GQTTS.CHALK I Attfisting of'fiicejbh: m'mis'si p f 0f Patents Eaten: No; 3,631,521 Dated December- 28. 1971 Itycncofls) DIETER FLOESSEL It is certified that: error appears inthe ab0ve-idcntiiicd pazem; and aha; said Letters Patent are hereby corrected as shown below:

' (I lame}; line '4, between the words "at"- i and .uiief insert the following:

- f its upper end, said b last' valve normally occu;pying' ajposioi on below the ports in said seoond se a le dthis 91 b 69y ofi- May 972;-

'At a EDw'gxRn im-FLETCHER{JRQ'- -R BE T OT T H K Atxte sting Officer",-

' Commissioner of Patents 

1. In an electrical circuit breaker structure of the gas blast type, the combination comprising a hollow columnar insulator, a low-pressure housing supported atop said columnar insulator and which leads to a chamber containing the circuit breaker contacts, a high-pressure housing storing a pressurized gas such as SF6 for contact separation and arc extinction and which is located adjacent said low-pressure housing, a blast valve-controlling communication between said high-pressure housing and said lowpressure housing, and a blocking-off member controlling communication between said high-pressure housing and said lowpressure housing and also controlling communication between the interior of said columnar insulator and said low-pressure housing, said blocking-off member being movable from a first position corresponding to the operating state of said circuit breaker and wherein said columnar insulator communicates with said low-pressure housing to a second position corresponding to the inspection state of said circuit breaker and wherein both said columnar insulator and said high-pressure housing are blocked off from said low-prEssure housing.
 2. An electrical circuit breaker structure as defined in claim 1 wherein said blocking-off member includes a lower tubular part slidably arranged in a first guide sleeve located within said low-pressure housing and which communicates with said columnar insulator, said lower tubular part of said blocking-off member being provided with apertures which when said blocking-off member occupies a lower position corresponding to the operating state of the circuit breaker are in registration with ports in said first guide sleeve to establish communication between said low-pressure housing and the interior of said columnar insulator, said blocking-off member further including an upper tubular part slidably arranged in a second guide sleeve established by an inner cylindrical wall of said high-pressure housing, said upper tubular part of said blocking-off member being provided with apertures which when said blocking-off member occupies its lower position are in registration with ports in said second guide sleeve to establish communication between said high-pressure housing and said low-pressure housing when said blast valve is actuated to effect a disconnection of the circuit breaker contacts, said blocking-off member being movable to an upper position corresponding to an inspection state of the circuit breaker to shift the apertures in the lower and upper tubular parts thereof out of registration with their respectively associated ports in said first and second guide sleeves thereby to block off communication between said low-pressure housing and said columnar insulator and high-pressure housing respectively.
 3. An electrical circuit breaker structure as defined in claim 2 wherein said blast valve is mounted for sliding movement as a piston in the upper tubular part of said blocking-off member which is closed off at its upper end, said blast valve normally occupying a position below the parts in second guide sleeve whereby the pressurized gas from said high-pressure housing is admitted to the interior of and applies an upward force against said blocking-off member tending to shift said blocking-off member to its upper position, and means for applying a releasable counter force to hold said blocking-off member in its lower position.
 4. An electrical circuit breaker structure as defined in claim 3 wherein said means for applying a releasable counter force holding said blocking-off member in its lower position is constituted by a sleeve member located above and which bears upon the upper tubular part of said blocking-off member, said sleeve member being guided for sliding movement in said second guide sleeve, said sleeve member terminating in a head including a plurality of circumferentially spaced apertures through which pass upstanding threaded stay bolts provided with nuts which bear upon the head.
 5. An electrical circuit breaker structure as defined in claim 3 wherein said blast valve is actuated by a rod extending upward through said columnar insulator and said tubular blocking-off member, the interior of said blocking-off member being provided with a transverse wall through which said blast valve actuator passes with a snug fit thereby enabling said transverse wall to function as a piston subjected to the gas pressure within said columnar insulator for applying an upward force to said blocking-off member. 